Skip to main content
Avalara Help Center

ACTION NEEDED: Illinois AvaTax Returns customers must submit valid IL-8633-B Business Electronic Filing Enrollment form


The IL-8633-B Business Electronic Filing Enrollment form is required in order for Avalara to file your Illinois returns with an electronic signature.

AvaTax Returns customers must submit Form IL-8633-B Business Electronic Filing Enrollment in order for Avalara to file your returns with an electronic signature.

AvaTax Returns customers are required to submit this form in advance of adding your Illinois scheduled return in Avatax. Once the state has processed your form, you will receive a confirmation letter from the state. The form is not retroactive, so will only cover periods after the state has processed the form. Periods prior where Avalara has submitted your return electronically MAY be subject to penalty and interest.

Per the state, you must complete Form IL-8633-B if you are a taxpayer using third party software to file returns and payments.

What you need to do

AvaTax Returns customers must submit Form IL-8633-B Business Electronic Filing Enrollment to the state of Illinois in order for Avalara to file your returns with an electronic signature.

See below for more information and specific details.


How to submit the IL-8633-B Business Electronic Filing Enrollment form to the state of Illinois

  1. In the Form IL-8633-B Business Electronic Filing Enrollment, complete Steps 1,2 and 5 only.  Avalara has completed Steps 3 and 4 on your behalf.
  2. Submit the completed form directly to the IL Department of Revenue (DOR) by one of the following methods:
    1. Email the completed form to the Illinois DOR at
    2. Fax it to the Illinois DOR at 217 782-7992.
    3. Mail it via USPS it to: Electronic Filing Section, Illinois Department of Revenue, PO Box 19479, Springfield, IL 62794-9479.

What happens if you do not submit the IL-8633-B as an AvaTax Returns customer?

Returns filed without the IL-8633-B on file or successfully processed with the state may be subject to a penalty. The state will disallow the timely-filing discount for that specific filing period and will assess an additional $250 penalty.

What will notices look like?

  1. Unprocessable – No Signature Letter: Without a valid 8633-B on file, the state will issue a monthly, retroactive non-signature letter to your company.  You will need to sign the letter and return it to the state via mail by the deadline indicated on the notice.  This will allow the state to accept the electronic signature submitted for that specific period.  If you do not sign by the date, the state will issue a $250 assessment for each period.  Note: The state will continue to issue non-signature letters for each filing period until a completed 8633-B is successfully submitted to the state. 
  2. Late-Filing Penalty Letter:  Without a valid 8633-B or signed non-signature letter on file for a specific period, the state will assess a $250 penalty. If you do not submit a valid 8633-B or signed non-signature letter, penalty and interest will continue to accrue for each filing period.

    On the Illinois DOR website, you will see this:

What will you see in AvaTax?

For AvaTax Returns customers: When you add the IL tax return form in AvaTax, you will be required to answer this question:

Has Illinois processed your IL-8633B form with our unique signature code on line 15?” 

Per the informational text provided there through the help bubble, Avalara customers are responsible for submitting the 8633b directly to the state prior to Avalara filing your returns.  Please see the section Submit form IL-8633-B in this Returns Central article: Set up Illinois Returns

If you have further questions

  • You can call the Illinois DOR office in Springfield, Illinois weekdays between 8:30 a.m. and 5:00 p.m. at 1-866-440-8680.
  • You can also visit the Illinois DOR web site, which features electronic filing information, forms, and booklets at